M40-M42 Interchange & M42 J4-7 DHS

Project Overview

Hill & Smith Infrastructure, BmJV and their delivery partners introduced a pioneering approach to installing central reserve rigid concrete barrier (RCB) across two major schemes on the Strategic Road Network.

The projects supported the SMP Alliance’s goal of moving construction off-site to improve safety, efficiency and programme certainty.

M40–M42 Interchange: Precast Foundations and Surface-Mounted H2 Barrier

At the M40–M42 Interchange, the team trialled and delivered a new RCB system using precast foundations and surface-mounted H2 concrete barriers.

Removed the need for drainage diversions
10.5km of barrier installed
Completed three months ahead of schedule

M42 J4–7 Dynamic Hard Shoulder: A New Low-Carbon H1 Barrier

The approach was refined and scaled up for the M42 J4–7 Dynamic Hard Shoulder Enhancement, where a newly developed low-carbon H1 barrier was introduced. Designed to integrate seamlessly with the H2 system, it contributed to a carbon saving of 129,760 kg CO₂e.

The Outcome

These projects show the impact of early engagement, collaborative learning and off-site innovation in delivering safer, faster and more sustainable outcomes across the UK’s road network.

Key Facts

Two schemes on the Strategic Road Network
Precast foundations and surface-mounted barriers built off-site
M40–M42: 10.5km, three months early
M42 J4–7: 129,760 kg CO₂e carbon saving

Download the full case study below to see how Hill & Smith Infrastructure delivered innovative barrier systems while adapting to complex site conditions, streamlining off-site construction and working closely with stakeholders.

Download the Full Case Study

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